Marine holding tank

Abstract

A marine holding tank receives an excrement and water charge from a toilet and converts such charge into vapor and ash components for efficient and hygienic storage and/or removal. The holding tank is provided both with a rotary mixer to form a liquid-solid mixture from the excrement and water and with a heating means to reduce the mixture by vaporizing the liquid and incinerating the solids, thereby to complete the charge conversion. The heating means consists of two heating elements with selective energization so that one element may be independently operated for low heating or the two elements may be simultaneously operated for high heating. The heating elements are part of an energizing circuit that is controlled by a D.C. circuit, with such control circuit being automatically operative to discontinue the heating process when the temperature in the tank has reached a preselected point and to maintain the energizing circuit closed irrespective of A.C. power failures or interruptions while being manually selectively controlled to start or stop the heating process and to heat at low or high capacities.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A holding tank in fluid communication with a toilet comprising a housing having intake port and exhaust port means, a basket mounted in said housing for receiving an excrement and water charge from the toilet through the intake port, rotary mixing means in said basket for mixing the excrement with the water, and heating means for said charge operated simultaneously with said mixing means, whereby said charge is reduced in the basket to a liquid-solid mixture and then to vapor and ashes for removal of the vapor and the ashes from the housing through the exhaust port means. 
     
     
       2. The tank of claim 1, wherein the mixing means comprises a motor mounted to said housing, a shaft rotatably driven by said motor and extending into said basket, and an impeller connected to the bottom end of the shaft, whereby rotation of said impeller in said basket mixes the excrement with the water to form a liquid-solid mixture. 
     
     
       3. The tank of claim 2, wherein the motor is carried on a cover plate and such plate is removably mounted to the top of the housing, with the shaft extending downwardly through the plate into the basket, the cover plate when removed providing easy access to the basket for cleaning or removal of the ashes. 
     
     
       4. A holding tank in fluid communication with a toilet comprising a housing having an intake port and exhaust port means, a basket mounted in said housing for receiving an excrement and water charge from the toilet through the intake port, rotary mixing means in said basket for mixing the water with the excrement, heating means for said charge to evaporate the liquid and incinerate the solids of such charge in said basket for removal of the same through the exhaust port means, an alternating current energizing circuit which includes said heating means and a direct current circuit for controlling the operation of said alternating current energizing circuit. 
     
     
       5. The tank of claim 4, wherein the control circuit when actuated closes the energizing circuit and maintains the energizing circuit in closed condition irrespective of alternating current power interruptions until the control circuit is deenergized. 
     
     
       6. The tank of claim 5, wherein the control circuit includes at least one relay that is continually operative during energization of the control circuit to maintain at least one set of relay contacts in the energizing circuit closed. 
     
     
       7. The tank of claim 4, wherein the heating means includes two heating elements, the control circuit selectively being operative to actuate at least one of such elements in the energizing circuit. 
     
     
       8. The tank of claim 7, wherein the energizing circuit includes two separate circuits operating from separate sources with each such separate circuit including at least a set of normally open relay contacts and a heating element, said control circuit including a relay circuit which is operative during energization to control the condition of the relay contacts in the energizing circuit. 
     
     
       9. The tank of claim 8, wherein the relay circuit of the control circuit includes a two position switch and one of said separate circuits in said energizing circuit energizes a motor connected to said rotary mixing means simultaneously with the energization of the heating means in said one separate circuit, one position of said switch being operative during energization of the control circuit to close only said one separate circuit of the energizing circuit and the other position of said switch being operative to close both said separate circuits of said energizing circuit. 
     
     
       10. The tank of claim 8, wherein the control circuit includes, in series with said relay circuit, a manual start switch, a manual off switch, and a thermostatic switch operative to open the circuit when the holding tank reaches a preselected temperature of approximately 270° F. 
     
     
       11. The tank of claim 4 wherein the control circuit includes a manual start switch operative to energize said control circuit which in turn conditions said energizing circuit for operation. 
     
     
       12. The tank of claim 11 wherein the control circuit may be deenergized for deactivating the energizing circuit for the heating means by a manually operated off switch unless the temperature in the heating tank reaches a predetermined temperature of approximately 270° F which results in automatic deenergization of said control circuit. 
     
     
       13. The tank of claim 7 wherein the motor for the mixing means is electrically connected in parallel with said one of such heating elements thereby simultaneously to operate said mixing means with said one of such heating elements.